Resistance to infection by subgroups B, D, and E avian sarcoma and leukosis viruses is explained by a premature stop codon within a resistance allele of the tvb receptor gene.

Here we present the first molecular characterization of the defect associated with an avian sarcoma and leukosis virus (ASLV) receptor resistance allele, tvb(r). We show that resistance to infection by subgroups B, D, and E ASLV is explained by the presence of a single base pair mutation that distinguishes this allele from tvb(s1), an allele which encodes a receptor for all three viral subgroups. This mutation generates an in-frame stop codon that is predicted to lead to the production of a severely truncated protein.